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[PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr

Konstantin Kostiuk posted 4 patches 2 years, 7 months ago
Maintainers: Konstantin Kostiuk <kkostiuk@redhat.com>, Michael Roth <michael.roth@amd.com>
There is a newer version of this series
[PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr
Posted by Konstantin Kostiuk 2 years, 7 months ago 
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
---
 qga/vss-win32/meson.build   |  2 +-
 qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
 qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 qga/vss-win32/vss-debug.cpp
 create mode 100644 qga/vss-win32/vss-debug.h

diff --git a/qga/vss-win32/meson.build b/qga/vss-win32/meson.build
index 9483ccd3b8..0ac918910b 100644
--- a/qga/vss-win32/meson.build
+++ b/qga/vss-win32/meson.build
@@ -7,7 +7,7 @@ link_args = cc.get_supported_link_arguments([
 
 qga_vss = shared_module(
   'qga-vss',
-  ['requester.cpp', 'provider.cpp', 'install.cpp', genh],
+  ['requester.cpp', 'provider.cpp', 'install.cpp', 'vss-debug.cpp', genh],
   name_prefix: '',
   cpp_args: ['-Wno-unknown-pragmas', '-Wno-delete-non-virtual-dtor', '-Wno-non-virtual-dtor'],
   link_args: link_args,
diff --git a/qga/vss-win32/vss-debug.cpp b/qga/vss-win32/vss-debug.cpp
new file mode 100644
index 0000000000..5d6f37944b
--- /dev/null
+++ b/qga/vss-win32/vss-debug.cpp
@@ -0,0 +1,31 @@
+/*
+ * QEMU Guest Agent VSS debug declarations
+ *
+ * Copyright (C) 2023 Red Hat Inc
+ *
+ * Authors:
+ *  Konstantin Kostiuk <kkostiuk@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "vss-debug.h"
+#include "vss-common.h"
+
+void qga_debug_internal(const char *funcname, const char *fmt, ...)  {
+    char user_sting[512] = {0};
+    char full_string[640] = {0};
+
+    va_list args;
+    va_start(args, fmt);
+    vsnprintf(user_sting, 512, fmt, args);
+    va_end(args);
+
+    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s %s\n",
+             GetCurrentThreadId(), funcname, user_sting);
+
+    OutputDebugString(full_string);
+    fprintf(stderr, "%s", full_string);
+}
diff --git a/qga/vss-win32/vss-debug.h b/qga/vss-win32/vss-debug.h
new file mode 100644
index 0000000000..7800457392
--- /dev/null
+++ b/qga/vss-win32/vss-debug.h
@@ -0,0 +1,25 @@
+/*
+ * QEMU Guest Agent VSS debug declarations
+ *
+ * Copyright (C) 2023 Red Hat Inc
+ *
+ * Authors:
+ *  Konstantin Kostiuk <kkostiuk@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include <vss-handles.h>
+
+#ifndef VSS_DEBUG_H
+#define VSS_DEBUG_H
+
+void qga_debug_internal(const char *funcname, const char *fmt, ...) G_GNUC_PRINTF(2, 3);
+
+#define qga_debug(fmt, ...) qga_debug_internal(__func__, fmt, ## __VA_ARGS__)
+#define qga_debug_begin qga_debug("begin")
+#define qga_debug_end qga_debug("end")
+
+#endif
-- 
2.34.1
Re: [PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr
Posted by Philippe Mathieu-Daudé 2 years, 7 months ago 
On 7/7/23 11:22, Konstantin Kostiuk wrote:
> Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
> ---
>   qga/vss-win32/meson.build   |  2 +-
>   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
>   qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
>   3 files changed, 57 insertions(+), 1 deletion(-)
>   create mode 100644 qga/vss-win32/vss-debug.cpp
>   create mode 100644 qga/vss-win32/vss-debug.h


> diff --git a/qga/vss-win32/vss-debug.cpp b/qga/vss-win32/vss-debug.cpp
> new file mode 100644
> index 0000000000..5d6f37944b
> --- /dev/null
> +++ b/qga/vss-win32/vss-debug.cpp
> @@ -0,0 +1,31 @@
> +/*
> + * QEMU Guest Agent VSS debug declarations
> + *
> + * Copyright (C) 2023 Red Hat Inc
> + *
> + * Authors:
> + *  Konstantin Kostiuk <kkostiuk@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "vss-debug.h"
> +#include "vss-common.h"
> +
> +void qga_debug_internal(const char *funcname, const char *fmt, ...)  {
> +    char user_sting[512] = {0};

"user_string"

> +    char full_string[640] = {0};
> +
> +    va_list args;
> +    va_start(args, fmt);
> +    vsnprintf(user_sting, 512, fmt, args);

ARRAY_SIZE(user_string)

> +    va_end(args);
> +
> +    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s %s\n",
> +             GetCurrentThreadId(), funcname, user_sting);

if (snprintf() <= 0) { return; }

> +
> +    OutputDebugString(full_string);
> +    fprintf(stderr, "%s", full_string);

Format unused:

fputs(full_string, stderr);

> +}

With the changes:
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Re: [PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr
Posted by Konstantin Kostiuk 2 years, 7 months ago 
On Fri, Jul 7, 2023 at 1:33 PM Philippe Mathieu-Daudé <philmd@linaro.org>
wrote:

> On 7/7/23 11:22, Konstantin Kostiuk wrote:
> > Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
> > ---
> >   qga/vss-win32/meson.build   |  2 +-
> >   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
> >   qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
> >   3 files changed, 57 insertions(+), 1 deletion(-)
> >   create mode 100644 qga/vss-win32/vss-debug.cpp
> >   create mode 100644 qga/vss-win32/vss-debug.h
>
>
> > diff --git a/qga/vss-win32/vss-debug.cpp b/qga/vss-win32/vss-debug.cpp
> > new file mode 100644
> > index 0000000000..5d6f37944b
> > --- /dev/null
> > +++ b/qga/vss-win32/vss-debug.cpp
> > @@ -0,0 +1,31 @@
> > +/*
> > + * QEMU Guest Agent VSS debug declarations
> > + *
> > + * Copyright (C) 2023 Red Hat Inc
> > + *
> > + * Authors:
> > + *  Konstantin Kostiuk <kkostiuk@redhat.com>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> later.
> > + * See the COPYING file in the top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "vss-debug.h"
> > +#include "vss-common.h"
> > +
> > +void qga_debug_internal(const char *funcname, const char *fmt, ...)  {
> > +    char user_sting[512] = {0};
>
> "user_string"
>
> > +    char full_string[640] = {0};
> > +
> > +    va_list args;
> > +    va_start(args, fmt);
> > +    vsnprintf(user_sting, 512, fmt, args);
>
> ARRAY_SIZE(user_string)
>

I have a problem with ARRAY_SIZE define.

../qga/vss-win32/vss-debug.cpp: In function 'void qga_debug_internal(const
char*, const char*, ...)':
/src/include/qemu/compiler.h:70:12: error: types may not be defined in
'sizeof' expressions
   70 |     struct { \
      |            ^
/src/include/qemu/compiler.h:78:43: note: in expansion of macro
'QEMU_BUILD_BUG_ON_STRUCT'
   78 | #define QEMU_BUILD_BUG_ON_ZERO(x)
(sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
      |                                           ^~~~~~~~~~~~~~~~~~~~~~~~
/src/include/qemu/osdep.h:474:24: note: in expansion of macro
'QEMU_BUILD_BUG_ON_ZERO'
  474 |                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
      |                        ^~~~~~~~~~~~~~~~~~~~~~
../qga/vss-win32/vss-debug.cpp:23:32: note: in expansion of macro
'ARRAY_SIZE'
   23 |     if (vsnprintf(user_string, ARRAY_SIZE(user_string), fmt, args)
<= 0) {
      |                                ^~~~~~~~~~
/src/include/qemu/osdep.h:470:57: error: expected primary-expression before
'typeof'
  470 | #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
      |                                                         ^~~~~~
/src/include/qemu/compiler.h:71:14: note: in definition of macro
'QEMU_BUILD_BUG_ON_STRUCT'
   71 |         int:(x) ? -1 : 1; \
      |              ^
/src/include/qemu/osdep.h:474:24: note: in expansion of macro
'QEMU_BUILD_BUG_ON_ZERO'
  474 |                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
      |                        ^~~~~~~~~~~~~~~~~~~~~~
/src/include/qemu/osdep.h:474:48: note: in expansion of macro
'QEMU_IS_ARRAY'
  474 |                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))


Can you help with this?


> > +    va_end(args);
> > +
> > +    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s %s\n",
> > +             GetCurrentThreadId(), funcname, user_sting);
>
> if (snprintf() <= 0) { return; }
>
> > +
> > +    OutputDebugString(full_string);
> > +    fprintf(stderr, "%s", full_string);
>
> Format unused:
>
> fputs(full_string, stderr);
>
> > +}
>
> With the changes:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>
>
Re: [PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr
Posted by Philippe Mathieu-Daudé 2 years, 7 months ago 
On 7/7/23 16:24, Konstantin Kostiuk wrote:
> 
> 
> On Fri, Jul 7, 2023 at 1:33 PM Philippe Mathieu-Daudé <philmd@linaro.org 
> <mailto:philmd@linaro.org>> wrote:
> 
>     On 7/7/23 11:22, Konstantin Kostiuk wrote:
>      > Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com
>     <mailto:kkostiuk@redhat.com>>
>      > ---
>      >   qga/vss-win32/meson.build   |  2 +-
>      >   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
>      >   qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
>      >   3 files changed, 57 insertions(+), 1 deletion(-)
>      >   create mode 100644 qga/vss-win32/vss-debug.cpp
>      >   create mode 100644 qga/vss-win32/vss-debug.h
> 
> 
>      > diff --git a/qga/vss-win32/vss-debug.cpp
>     b/qga/vss-win32/vss-debug.cpp
>      > new file mode 100644
>      > index 0000000000..5d6f37944b
>      > --- /dev/null
>      > +++ b/qga/vss-win32/vss-debug.cpp
>      > @@ -0,0 +1,31 @@
>      > +/*
>      > + * QEMU Guest Agent VSS debug declarations
>      > + *
>      > + * Copyright (C) 2023 Red Hat Inc
>      > + *
>      > + * Authors:
>      > + *  Konstantin Kostiuk <kkostiuk@redhat.com
>     <mailto:kkostiuk@redhat.com>>
>      > + *
>      > + * This work is licensed under the terms of the GNU GPL, version
>     2 or later.
>      > + * See the COPYING file in the top-level directory.
>      > + */
>      > +
>      > +#include "qemu/osdep.h"
>      > +#include "vss-debug.h"
>      > +#include "vss-common.h"
>      > +
>      > +void qga_debug_internal(const char *funcname, const char *fmt,
>     ...)  {
>      > +    char user_sting[512] = {0};
> 
>     "user_string"
> 
>      > +    char full_string[640] = {0};
>      > +
>      > +    va_list args;
>      > +    va_start(args, fmt);
>      > +    vsnprintf(user_sting, 512, fmt, args);
> 
>     ARRAY_SIZE(user_string)
> 
> 
> I have a problem with ARRAY_SIZE define.
> 
> ../qga/vss-win32/vss-debug.cpp: In function 'void 
> qga_debug_internal(const char*, const char*, ...)':
> /src/include/qemu/compiler.h:70:12: error: types may not be defined in 
> 'sizeof' expressions
>     70 |     struct { \
>        |            ^
> /src/include/qemu/compiler.h:78:43: note: in expansion of macro 
> 'QEMU_BUILD_BUG_ON_STRUCT'
>     78 | #define QEMU_BUILD_BUG_ON_ZERO(x) 
> (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
>        |                                           ^~~~~~~~~~~~~~~~~~~~~~~~
> /src/include/qemu/osdep.h:474:24: note: in expansion of macro 
> 'QEMU_BUILD_BUG_ON_ZERO'
>    474 |                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
>        |                        ^~~~~~~~~~~~~~~~~~~~~~
> ../qga/vss-win32/vss-debug.cpp:23:32: note: in expansion of macro 
> 'ARRAY_SIZE'
>     23 |     if (vsnprintf(user_string, ARRAY_SIZE(user_string), fmt, 
> args) <= 0) {
>        |                                ^~~~~~~~~~
> /src/include/qemu/osdep.h:470:57: error: expected primary-expression 
> before 'typeof'
>    470 | #define QEMU_IS_ARRAY(x) 
> (!__builtin_types_compatible_p(typeof(x), \
>        |                                                         ^~~~~~
> /src/include/qemu/compiler.h:71:14: note: in definition of macro 
> 'QEMU_BUILD_BUG_ON_STRUCT'
>     71 |         int:(x) ? -1 : 1; \
>        |              ^
> /src/include/qemu/osdep.h:474:24: note: in expansion of macro 
> 'QEMU_BUILD_BUG_ON_ZERO'
>    474 |                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
>        |                        ^~~~~~~~~~~~~~~~~~~~~~
> /src/include/qemu/osdep.h:474:48: note: in expansion of macro 
> 'QEMU_IS_ARRAY'
>    474 |                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> 
> Can you help with this?

Eh no clue, maybe not C++ compliant?

Fall back to sizeof() ¯\_(ツ)_/¯

> 
> 
>      > +    va_end(args);
>      > +
>      > +    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s %s\n",
>      > +             GetCurrentThreadId(), funcname, user_sting);
> 
>     if (snprintf() <= 0) { return; }
> 
>      > +
>      > +    OutputDebugString(full_string);
>      > +    fprintf(stderr, "%s", full_string);
> 
>     Format unused:
> 
>     fputs(full_string, stderr);
> 
>      > +}
> 
>     With the changes:
>     Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org
>     <mailto:philmd@linaro.org>>
>
Re: [PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr
Posted by Konstantin Kostiuk 2 years, 7 months ago 
On Fri, Jul 7, 2023 at 6:36 PM Philippe Mathieu-Daudé <philmd@linaro.org>
wrote:

> On 7/7/23 16:24, Konstantin Kostiuk wrote:
> >
> >
> > On Fri, Jul 7, 2023 at 1:33 PM Philippe Mathieu-Daudé <philmd@linaro.org
> > <mailto:philmd@linaro.org>> wrote:
> >
> >     On 7/7/23 11:22, Konstantin Kostiuk wrote:
> >      > Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com
> >     <mailto:kkostiuk@redhat.com>>
> >      > ---
> >      >   qga/vss-win32/meson.build   |  2 +-
> >      >   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
> >      >   qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
> >      >   3 files changed, 57 insertions(+), 1 deletion(-)
> >      >   create mode 100644 qga/vss-win32/vss-debug.cpp
> >      >   create mode 100644 qga/vss-win32/vss-debug.h
> >
> >
> >      > diff --git a/qga/vss-win32/vss-debug.cpp
> >     b/qga/vss-win32/vss-debug.cpp
> >      > new file mode 100644
> >      > index 0000000000..5d6f37944b
> >      > --- /dev/null
> >      > +++ b/qga/vss-win32/vss-debug.cpp
> >      > @@ -0,0 +1,31 @@
> >      > +/*
> >      > + * QEMU Guest Agent VSS debug declarations
> >      > + *
> >      > + * Copyright (C) 2023 Red Hat Inc
> >      > + *
> >      > + * Authors:
> >      > + *  Konstantin Kostiuk <kkostiuk@redhat.com
> >     <mailto:kkostiuk@redhat.com>>
> >      > + *
> >      > + * This work is licensed under the terms of the GNU GPL, version
> >     2 or later.
> >      > + * See the COPYING file in the top-level directory.
> >      > + */
> >      > +
> >      > +#include "qemu/osdep.h"
> >      > +#include "vss-debug.h"
> >      > +#include "vss-common.h"
> >      > +
> >      > +void qga_debug_internal(const char *funcname, const char *fmt,
> >     ...)  {
> >      > +    char user_sting[512] = {0};
> >
> >     "user_string"
> >
> >      > +    char full_string[640] = {0};
> >      > +
> >      > +    va_list args;
> >      > +    va_start(args, fmt);
> >      > +    vsnprintf(user_sting, 512, fmt, args);
> >
> >     ARRAY_SIZE(user_string)
> >
> >
> > I have a problem with ARRAY_SIZE define.
> >
> > ../qga/vss-win32/vss-debug.cpp: In function 'void
> > qga_debug_internal(const char*, const char*, ...)':
> > /src/include/qemu/compiler.h:70:12: error: types may not be defined in
> > 'sizeof' expressions
> >     70 |     struct { \
> >        |            ^
> > /src/include/qemu/compiler.h:78:43: note: in expansion of macro
> > 'QEMU_BUILD_BUG_ON_STRUCT'
> >     78 | #define QEMU_BUILD_BUG_ON_ZERO(x)
> > (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
> >        |
> ^~~~~~~~~~~~~~~~~~~~~~~~
> > /src/include/qemu/osdep.h:474:24: note: in expansion of macro
> > 'QEMU_BUILD_BUG_ON_ZERO'
> >    474 |
>  QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> >        |                        ^~~~~~~~~~~~~~~~~~~~~~
> > ../qga/vss-win32/vss-debug.cpp:23:32: note: in expansion of macro
> > 'ARRAY_SIZE'
> >     23 |     if (vsnprintf(user_string, ARRAY_SIZE(user_string), fmt,
> > args) <= 0) {
> >        |                                ^~~~~~~~~~
> > /src/include/qemu/osdep.h:470:57: error: expected primary-expression
> > before 'typeof'
> >    470 | #define QEMU_IS_ARRAY(x)
> > (!__builtin_types_compatible_p(typeof(x), \
> >        |                                                         ^~~~~~
> > /src/include/qemu/compiler.h:71:14: note: in definition of macro
> > 'QEMU_BUILD_BUG_ON_STRUCT'
> >     71 |         int:(x) ? -1 : 1; \
> >        |              ^
> > /src/include/qemu/osdep.h:474:24: note: in expansion of macro
> > 'QEMU_BUILD_BUG_ON_ZERO'
> >    474 |
>  QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> >        |                        ^~~~~~~~~~~~~~~~~~~~~~
> > /src/include/qemu/osdep.h:474:48: note: in expansion of macro
> > 'QEMU_IS_ARRAY'
> >    474 |
>  QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
> >
> > Can you help with this?
>
> Eh no clue, maybe not C++ compliant?
>
> Fall back to sizeof() ¯\_(ツ)_/¯
>
>
You are right, When I rename the file to vss-debug.c the error disappears.
What is the better solution:
1) use vss-debug.c and extern "C" { #include "vss-debug.h" } in CPP files
2) just use sizeof() in CPP


> >
> >
> >      > +    va_end(args);
> >      > +
> >      > +    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s
> %s\n",
> >      > +             GetCurrentThreadId(), funcname, user_sting);
> >
> >     if (snprintf() <= 0) { return; }
> >
> >      > +
> >      > +    OutputDebugString(full_string);
> >      > +    fprintf(stderr, "%s", full_string);
> >
> >     Format unused:
> >
> >     fputs(full_string, stderr);
> >
> >      > +}
> >
> >     With the changes:
> >     Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org
> >     <mailto:philmd@linaro.org>>
> >
>
>
Re: [PATCH v3 1/4] QGA VSS: Add wrapper to send log to debugger and stderr
Posted by Thomas Huth 2 years, 7 months ago 
On 07/07/2023 22.22, Konstantin Kostiuk wrote:
> 
> 
> On Fri, Jul 7, 2023 at 6:36 PM Philippe Mathieu-Daudé <philmd@linaro.org 
> <mailto:philmd@linaro.org>> wrote:
> 
>     On 7/7/23 16:24, Konstantin Kostiuk wrote:
>      >
>      >
>      > On Fri, Jul 7, 2023 at 1:33 PM Philippe Mathieu-Daudé
>     <philmd@linaro.org <mailto:philmd@linaro.org>
>      > <mailto:philmd@linaro.org <mailto:philmd@linaro.org>>> wrote:
>      >
>      >     On 7/7/23 11:22, Konstantin Kostiuk wrote:
>      >      > Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com
>     <mailto:kkostiuk@redhat.com>
>      >     <mailto:kkostiuk@redhat.com <mailto:kkostiuk@redhat.com>>>
>      >      > ---
>      >      >   qga/vss-win32/meson.build   |  2 +-
>      >      >   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
>      >      >   qga/vss-win32/vss-debug.h   | 25 +++++++++++++++++++++++++
>      >      >   3 files changed, 57 insertions(+), 1 deletion(-)
>      >      >   create mode 100644 qga/vss-win32/vss-debug.cpp
>      >      >   create mode 100644 qga/vss-win32/vss-debug.h
>      >
>      >
>      >      > diff --git a/qga/vss-win32/vss-debug.cpp
>      >     b/qga/vss-win32/vss-debug.cpp
>      >      > new file mode 100644
>      >      > index 0000000000..5d6f37944b
>      >      > --- /dev/null
>      >      > +++ b/qga/vss-win32/vss-debug.cpp
>      >      > @@ -0,0 +1,31 @@
>      >      > +/*
>      >      > + * QEMU Guest Agent VSS debug declarations
>      >      > + *
>      >      > + * Copyright (C) 2023 Red Hat Inc
>      >      > + *
>      >      > + * Authors:
>      >      > + *  Konstantin Kostiuk <kkostiuk@redhat.com
>     <mailto:kkostiuk@redhat.com>
>      >     <mailto:kkostiuk@redhat.com <mailto:kkostiuk@redhat.com>>>
>      >      > + *
>      >      > + * This work is licensed under the terms of the GNU GPL, version
>      >     2 or later.
>      >      > + * See the COPYING file in the top-level directory.
>      >      > + */
>      >      > +
>      >      > +#include "qemu/osdep.h"
>      >      > +#include "vss-debug.h"
>      >      > +#include "vss-common.h"
>      >      > +
>      >      > +void qga_debug_internal(const char *funcname, const char *fmt,
>      >     ...)  {
>      >      > +    char user_sting[512] = {0};
>      >
>      >     "user_string"
>      >
>      >      > +    char full_string[640] = {0};
>      >      > +
>      >      > +    va_list args;
>      >      > +    va_start(args, fmt);
>      >      > +    vsnprintf(user_sting, 512, fmt, args);
>      >
>      >     ARRAY_SIZE(user_string)
>      >
>      >
>      > I have a problem with ARRAY_SIZE define.
>      >
>      > ../qga/vss-win32/vss-debug.cpp: In function 'void
>      > qga_debug_internal(const char*, const char*, ...)':
>      > /src/include/qemu/compiler.h:70:12: error: types may not be defined in
>      > 'sizeof' expressions
>      >     70 |     struct { \
>      >        |            ^
>      > /src/include/qemu/compiler.h:78:43: note: in expansion of macro
>      > 'QEMU_BUILD_BUG_ON_STRUCT'
>      >     78 | #define QEMU_BUILD_BUG_ON_ZERO(x)
>      > (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
>      >        |                                          
>     ^~~~~~~~~~~~~~~~~~~~~~~~
>      > /src/include/qemu/osdep.h:474:24: note: in expansion of macro
>      > 'QEMU_BUILD_BUG_ON_ZERO'
>      >    474 |                      
>       QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
>      >        |                        ^~~~~~~~~~~~~~~~~~~~~~
>      > ../qga/vss-win32/vss-debug.cpp:23:32: note: in expansion of macro
>      > 'ARRAY_SIZE'
>      >     23 |     if (vsnprintf(user_string, ARRAY_SIZE(user_string), fmt,
>      > args) <= 0) {
>      >        |                                ^~~~~~~~~~
>      > /src/include/qemu/osdep.h:470:57: error: expected primary-expression
>      > before 'typeof'
>      >    470 | #define QEMU_IS_ARRAY(x)
>      > (!__builtin_types_compatible_p(typeof(x), \
>      >        |                                                         ^~~~~~
>      > /src/include/qemu/compiler.h:71:14: note: in definition of macro
>      > 'QEMU_BUILD_BUG_ON_STRUCT'
>      >     71 |         int:(x) ? -1 : 1; \
>      >        |              ^
>      > /src/include/qemu/osdep.h:474:24: note: in expansion of macro
>      > 'QEMU_BUILD_BUG_ON_ZERO'
>      >    474 |                      
>       QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
>      >        |                        ^~~~~~~~~~~~~~~~~~~~~~
>      > /src/include/qemu/osdep.h:474:48: note: in expansion of macro
>      > 'QEMU_IS_ARRAY'
>      >    474 |                      
>       QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
>      >
>      > Can you help with this?
> 
>     Eh no clue, maybe not C++ compliant?
> 
>     Fall back to sizeof() ¯\_(ツ)_/¯
> 
> 
> You are right, When I rename the file to vss-debug.c the error disappears.
> What is the better solution:
> 1) use vss-debug.c and extern "C" { #include "vss-debug.h" } in CPP files
> 2) just use sizeof() in CPP

I recently sent a patch to drop the logic for linking C code with C++ code:

  https://lists.gnu.org/archive/html/qemu-devel/2023-07/msg01553.html

So please go with option 2 ;-)

  Thomas

Patchew 2.1-devel-b67e4c2

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